What if we are wrong about the lionfish invasion? Craig Layman North Carolina State University

Transcription

1 What if we are wrong about the lionfish invasion? Craig Layman North Carolina State University

2 Lionfish prove to be tireless terminator-like invasive species

3 Godzilla Lionfish Threatening Cayman Paradise

4 In our waters these fishes are consuming everything. They eat everything on a reef. You have a beautiful little patch reef covered with a rainbow of fish and you come back after a lionfish has been there for five weeks and 80% of those fish are gone.

5 It s like an oil spill that keeps reproducing and will keep reproducing.forever

6 One of the top 15 horizon global conservation issues for 2010

7 Invasive Species Introduced by humans to an area where it didn t occur naturally Established a breeding population Populations reach sizes that cause severe environmental harm Many exotic species are not invasive

8 The most destructive invasive species are often predators

9 Spartina Salt marsh grass European green crab The vast majority of coastal invaders are low in the food web (plants or animals that eat plants) Asian Clam

10 Lionfish are the most successful invasive marine predator

11 How did they get here?

12 Lionfish spread through the western Atlantic and Caribbean: 1985 to 2013

13 Why So Successful? Numerous introductions Reproduce frequently Large number of eggs Long pelagic larval phase Venomous spines (dorsal, anal, and pelvic) Naïve predators and prey (enemy release) Thrive in degraded habitats Generalists Rapid growth

14 Research has proliferated almost as fast as have many debates

15 Do Prey Recognize Lionfish as a Threat? Antón et al. MEPS In press

16 Do Prey Recognize Lionfish as a Threat? Antón et al. MEPS In press

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18 Jets of Water Directed at Prey Adaptation vs. Exaptation Albins and Lyons 2012 MEPS

19 Invasive Species Introduced by humans to an area where it didn t occur naturally Established a breeding population Populations reach sizes that cause severe environmental harm Many exotic species are not invasive

20 Do lionfish actually alter prey communities?

21 The Seminal Experiment 80% reduction in juvenile fish densities Albins and Hixon 2008 MEPS

22 Layman, et al Marine Biology

23 Scale of Experiments is Critical At least four caveats are apparent in this study. Most importantly, individual lionfish were confined to a relatively small area, which may have resulted in disproportionate effects on fauna within cages. As such, we do not suggest using these data to infer actual interaction strengths between lionfish and prey.

24 The Invasion Viewed from Ecosystem Scales Impacts of invasive lionfish are not apparent on fish community structure on the Mesoamerican Barrier Reef, Belize (In Press, Ecosphere)

25 So Why Do We Not See Lionfish Effects at Larger Spatial Scales? *Food web interactions more diffuse at larger spatial scales *Actual densities may be lower across entire reef tracts *Recruitment so high, it swamps predator effects *High connectivity

26 So what should we do if anything - about the lionfish invasion?

27 Coastal Conservation and Management is an Exercise in Prioritization

28 An important point.. It is definitively an issue of local control rather than eradication Lionfish at 1000ft detected by the private submarine Nemo

29 Found in Diverse Habitat Types Courtesy of Mark Hixon, Oregon State

30 Lionfish Reproduction *15,000 eggs during a single spawning event Female Egg Mass *Adult females can lay eggs as many as 8 times a month *Males can be sexually mature at size <4 inches *Larval fish float in ocean currents for ~30 days

31 Lionfish Derbies and Similar Efforts Do Contribute to Localized Control

32 Should it be an International Priority? *Global microplastic pollution *Incorporating artificial life into natural systems *Stratospheric aerosols *Genetic techniques to eradicate mosquitoes *Increases in productivity of polar oceans *Protected area failure *Climate governance

33 Should it Be a Regional Priority in The Bahamas? *Bonefish industry valued at $141 million *Seagrasses cover 65,000km 2 a vast source of blue carbon storage *Millions of acres of protected areas that need enforcement *Is mangrove die-off incidence increasing? *Constant development pressures

34 So How Has This Emerged as Such a High Profile, Priority, Issue? *It is easy to envision and grasp as an environmental problem *A charismatic, sexy, animal *Easier for the media to convey to the public than other environmental challenges *We can see effects of management effects immediately *Give us a feeling we are making a difference

35 So What is the Way Forward with Respect to the Lionfish Invasion? *A move away from lionfish-centric studies *Incorporating lionfish into general ecological theory *Better incorporate cost-benefit considerations into allocating time and money to lionfish research *Remembering the difference between factual and judgment statements with respect to invasive species

36 Invasive Species Introduced by humans to an area where it didn t occur naturally Established a breeding population Populations reach sizes that cause severe environmental harm Many exotic species are not invasive

37 In Defense of the Invaders Most campaigns against foreign plants and animals are pointless, and some are worse than that The Economist December 5, 2015

38 More on lionfish over at Abaco Scientist cals.ncsu.edu/absci/

39 What if we are wrong about the lionfish invasion? Questions and discussion